A light emission assembly for weapon sights which provides a viewable illuminated aiming indicia of substantially fixed area and uniform brightness regardless of the ambient light conditions.
Certain conventional weapon sights use light gathering elements such as optical fiber(s), fluorescent fibers, or the like, to transmit ambient light to one or both ends to provide an aiming indicia useful in aiming a weapon. Improvements have been made over time to locate an artificial light source (such as tritium gas-filled, thin glass capsules whose inner surfaces are coated with a phosphor, light emitting diodes, or like) adjacent the external surfaces of the light gathering fibers to provide an aiming indicia useful in aiming the weapon even in low ambient light or darkness. For example, U.S. Pat. No. 6,216,352 and U.S. Pat. No. 6,122,833 each describe a sight for weapons which includes an elongated optical fiber of light gathering plastic having a first end at which light is emitted to provide an aiming indicia and location of an elongated, phosphorescent, light-emitting element disposed adjacent the outer surface of the elongated optical fiber, or as to certain embodiments, at the transverse end wall defining the second end of the elongated optical fiber.
However, there are certain disadvantages with these types of conventional weapon sights in that the installation of the light gathering element and the light emitting element in proper dimensional relation to achieve sufficient brightness of the aiming indicia can be difficult. In some cases, the light gathering element or the light emitting element can migrate due to a failure in whole or in part of the means for attaching these components to the weapon sight, such as a failure of adhesive.
Additionally, because the light emitting material often used is tritium capsule, the assembly of the tritium capsule adjacent the outer surface of the light gathering fiber may require an additional casing to enclose the assembly to obviate damage to the tritium capsule and to address safety concerns of using an uncontained a radio-isotope.
Moreover, conventional light gathering elements can have an overall length which acts to reduce the field of illumination of the aiming indicia which in turn can reduce accuracy in aiming the weapon. The longer the fiber the greater the attenuation losses, due to transmissivity, refraction, and reflection of light. As to particular conventional weapon sights which locate a tritium capsule adjacent the transverse end wall defining the second end of the elongated optical fiber, the overall length of the light gathering element becomes the sum of the light gathering element and the light emitting element which acts to further increase the overall length and acts to further exacerbate attenuation losses which reduce brightness of the field of illumination of the aiming indicia.
Additionally, the longer length of conventional light gathering elements along with the light emitting element, the shorter the sight radius (the distance between the visible part of the front sight and the visible part of the back sight). The shortened sight radius can have a detrimental effect on accuracy of aiming the weapon.
Moreover, the longer length of conventional light gathering elements can mechanically interfere with holstering the weapon or use of the weapon with other weapon paraphernalia.
The instant invention provides a weapon sight light emission assembly which overcomes in whole or in part certain of the forgoing disadvantages of conventional illuminated weapon sights.